Additive manufacturing processes for manufacturing three-dimensional objects by depositing constituent materials in a layer-by-layer manner according to the cross-sectional data of target three-dimensional objects have recently been receiving attention as methods for producing three-dimensional objects.
Japanese Patent Laid-Open No. 2003-53849 discloses a build-up method in which a powder composed of a thermoplastic material is arranged by an electrophotographic method according to the cross-sectional data of a three-dimensional object, and then the thermoplastic material in the form of particles are fused together in a layer-by-layer manner.
When a complicated three-dimensional object including, for example, an overhang structure or a structure including a moving part is manufactured by the additive manufacturing process, a structural material needs to be arranged on a region where the structural material is not present. In such a case, at least two thermoplastic materials, i.e., the structural material that constitutes a target three-dimensional object and a support material that supports the lamination of the structural material, need to be used as constituent materials.
A support portion composed of the support material is arranged in a region where the target three-dimensional object is not present in the additive manufacturing process. The support portion supports the structural material arranged on the region where the structural material is not present, and the support portion is eventually removed. Thus, the support material is desirably composed of a material that can be easily removed from a surface of the object composed of the structural material.
PCT Japanese Translation Patent Publication No. 2002-516346 discloses a technique using poly(2-ethyl-2-oxazoline), which is an aqueous organic material, as a support material. The use of the aqueous organic material as a support material can remove a support portion by washing with water.